According to a conventional organic EL panel, deterioration of an organic EL element because of exposure of the organic EL element to oxygen, moisture, and the like is prevented by the following sealing can structure commonly used: a desiccant is attached to a sealing can (concave glass can) and a sealing resin is disposed into a frame shape outside the outer periphery of an organic EL element. However, it is difficult to provide the organic EL panel having this sealing can structure with a top-emission structure because in the top-emission structure, light is outputted from an upper surface of the panel (i.e., an increase in aperture ratio is difficult), and further, a reduction in thickness of the panel is also difficult. Hence, research and development on a sealing structure where a flat substrate is used (hereinafter, also referred to as a “flat sealing structure” are now being made.
According to this flat sealing structure, it is necessary to form a film of an adhesive free from air bubbles into a specific pattern between the substrates. Organic EL panels having such a flat sealing structure have been disclosed as follows. According to the following organic EL panel having a flat sealing structure (see Patent Document 1, for example), a protective barrier (sealing material) is disposed on an attachment surface of a sealing substrate to intercept a emission area and its peripheral electrode region of a panel substrate, and an uncured sealing resin (filler) is applied on the inner side of the protective barrier on an attachment surface of the panel substrate, and the panel substrate is attached to the sealing substrate with the protective barrier and the cured sealing resin. According to the organic EL panel of Patent Document 1, an uncured sealing resin applied to a emission area cannot be dispersed on an electrode region side by a protective barrier formed around the emission area, and can be cured in the later step and thereby formed in each emission area Patent Document 2, for example, discloses an organic EL panel that can maintain stable light-emission characteristics for a long period of time by sealing a space between an element substrate and a sealing substrate with a sheet sealing member that covers an organic EL element, and a liquid sealing member disposed around the sheet sealing member. Further, according to the following sealing process aiming at simplification of steps (see Patent Document 3, for example), only a solid sealing resin instead of the liquid sealing resin (filler), which needs the protective barrier (sealing material), is used to cover each light-emitting region on a panel substrate.
[Patent Document 1]
Japanese Kokai Publication No. 2003-178866
[Patent Document 2]
WO 2008/078648
[Patent Document 3]
Japanese Kokai Publication No. 2006-179352